Improvement in elevators



'NTTED STATES PATENT GFFIOE,

' MARTIN L. WYMAN, OF BOSTON MASSACHUSETTS, ASSIGNOR TO. HIMSELF AND CHARLES E. MOORE, OF SAME PLAGE.

Y. IMPROVEMENT IN ELEVATORS. Y

Specification forming part of Letters Patent No. 174, 172, dated February 29, 1876; application led September 11, 1875.

To all-'whom 'it may concern:

Be it known that I,- MARTIN L. WYMAN, of Boston, in the county of Suffolk and State of Massachusetts, have invented Improvements in Elevators, ofpwhich the following is a specitication: y

This invention relates to improvements in elevators; and consists in devices to prevent the unwinding` of thcsuspensory when the descent of the car is for any reason obstruct ed, the operation being automatic and being thrown into action when the caris obstructed.

Figure l is a side view, and Fig. 2 a top view, of sufticient of ail/elevator to illustrate this invention; and Fig. 3 is a detail.

111 the drawing, ajis the car and b the guide or surroundings in which the car moves, they being of any well-.known or ordinary construction. At, ljneferably, the upper portion of the building containing the velevator is placed, in

suitable bearings, a shaft, c, on which is secured a worin-toothed wheel, d, and a hub, e,

' provided with a pawlpin,f, adapted toengage teeth or depressions g in the inner face ofthe drum t', adapted to receive the suspensory j. one or lnore of any well-known kind, and also vprovided with teeth h, to be engaged by a pawl, lc, shown as pivoted to a standard, l,

and provided with a piu or-arln, m, to enter a groove, a, in or to connect with a collar on the shaft o, which aotuates the shaft c through a worm-gear, p, thereon, which engages wheel d. This shaft ois driven or rotated alternately in either direction by any well-known mechanism, and is allowed end play in its bearings, a spring, q, being arranged to press the shaft in the direction of the arrow L, and a stop, 1', or other device prevents the shaft moving too far in the opposite direction. The weight'of the car on the suspensory, acting through the' drlnn, causes the worm-toothed wheel Lacting through the worin-gear p, to press the shaft o iu a direction lopposite the arrow l, and in such position the pawl k is held from contact with the teeth h on the drum t', and

the suspensory always remains taut thereon. If the descent of the car is obstructed its weight no longer acts on the drum to cause the wheel cl to press the shaft o against stop fr, or in that direction, and then the shaft o is moved by the spring g in the direction of the arrow 1, and through its connection with the lnstead of the shaft o, at right angles to the' shaft c, and its worm p, I might arrange at the rear of the shaft c, or at the right-hand side,

Fig. 1, a shaft parallel with shaft e, and on it Y I would place a toothed wheel or pinion to engage a toothed wheel on c in the position of wheel d, and I would'{niount this shaft in bearings, so that when the weight 'of the car ceases to act through the drum i and shaft to keep the shaft in olie position it should move ,under the action of a spring or otherwise and move a pawl to engage the teeth h. I claini- The combination of the hoisting-drum of an elevator and its shaft, connected, substantially as described, with a rotating shaft to actuate the drum-shaft and a pawl, the rotating shaft being adapted to move independently of its rotation and actuate the pawl to engage and hold the drum when the descent of the car is obstructed, substantially as described. In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

f 'MARTIN L. WYMAN. Witnesses:

THEO. vP. BROWN, T. G. SMITH. 

